The new Stumpjumper ST uses new tube shapes and an asymmetrical design to ensure that you get awesome ride characteristics. So get ready, because the Stumpjumper ST Alloy 29 is sure to exceed your expectations of how a trail bike should ride.
Our design goal for the new Stumpjumper was simple—build the ultimate trail bike, one that feels telepathic. And it turns out that this feeling all comes down to stiffness. Think of it this way: when the frame's telling your hands one thing and your feet another, your brain gets confused with the imbalance and the bike feels unstable. In order to fix this, we had to get to work on dialing-in the materials and shapes.
We continued down the suspension path with a custom Rx Trail Tune on both the fork and rear shock. Suspension performance is highly dependent on frame, wheel, and rider size, so we use our Rx Tune to get each bike to land in the middle of the adjustment spectrum, and this gives you the biggest possible range to fine-tune your ride. Another focal point of the tune was matching the suspension characteristics between wheel sizes—we developed a specific Rx Tune for each platform. So, no matter what wheel size you prefer, you'll get perfectly linear suspension.
Steps were also taken to make this bike easy to live with. Threaded bottom brackets make a triumphant return, and we made room for up to a 2.6" tire. You're also free to run whatever aftermarket rear shock you want, since we're using standard metric shocks. And customization is furthered with a Flip Chip that lets you to dial-in your Stumpy to your riding style. Switch it from High to Low and it drops your bottom bracket 6mm and slackens the head tube by half-a-degree. Little details also jump out to surprise you, like a newly designed ribbed chainstay protector that makes chain slap a thing of the past and nearly silences the drivetrain.
The build here is no-nonsense with a focus on dependable, high-performing parts, like Shimano SLX front and rear derailleurs, Tektro Gemini disc brakes, a RockShox Recon RL fork with 130mm of travel, a custom X-Fusion 02 Pro RL rear shock with 120mm of travel, and wide alloy wheels.
•Bottom Bracket: SRAM Power Spline
•Cassette: SunRace, 11-speed, 11-46t
•Chain: KMC X11, 11-speed w/ Missing Link™
•Crankset: SRAM NX, Boost™, direct-mount XSYNC, Powerspline
•Fork: RockShox Recon RL, Solo Air, 51mm offset, rebound adjust, lockout, 15x110mm Boost™ Maxle® Lite thru-axle, 130mm of travel
•Frame: M5 alloy chassis and rear end, asymmetrical design, 29 Trail Geometry, threaded BB, fully enclosed internal cable routing, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 120mm of travel
•Front Brake: Tektro Gemini Comp, hydraulic disc, resin pad, 200mm rotor
•Front Hub: Specialized, sealed cartridge bearings, 15x110mm spacing, 32h
•Front Tire: Butcher, GRID Casing, GRIPTON® compound, 2Bliss Ready, 29x2.3"
•Grips: Specialized Sip Grip, half-waffle, slip-on
•Inner Tubes: Standard, Presta valve
•Rear Brake: Tektro Gemini Comp, hydraulic disc, resin pad, 180mm rotor
•Rear Derailleur: Shimano SLX, Shadow Plus, 11-speed
•Rear Hub: Specialized, sealed cartridge bearings, 12x148mm thru-axle, 32h
•Rear Shock: X-Fusion 02 Pro RL, Rx Trail Tune, rebound adjust, lockout 190x42.5mm
•Rear Tire: Purgatory, GRID casing, GRIPTON® compound, 2Bliss Ready, 29x2.3"
•Rims: 700C disc, double-wall alloy, pinned
•Saddle: Body Geometry Henge Sport, steel rails, 143mm
•Seat Binder: Specialized bolt-type, alloy, 38.6mm
•Seatpost: Alloy, two-bolt clamp, 34.9mm
•Shift Levers: Shimano SLX, 11-speed
•Spokes: Stainless, 14g
•Stem: Specialized, 3D-forged alloy, 4-bolt, 7-degree rise
•Pedals: Specialized Dirt